/*
 * Copyright (C) 2009-2011 Big Muscle, http://strongdc.sf.net
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifndef _UDPSOCKET_H
#define _UDPSOCKET_H

#include "../client/AdcCommand.h"
#include "../client/CID.h"
#include "../client/FastAlloc.h"
#include "../client/MerkleTree.h"
#include "../client/Socket.h"
#include "../client/Thread.h"

namespace dht
{

struct Packet :
		FastAlloc<Packet>
{
	/** Public constructor */
	Packet(const string& ip_, uint16_t port_, const std::string& data_, const CID& _targetCID, const CID& _udpKey) :
		ip(ip_), port(port_), data(data_), targetCID(_targetCID), udpKey(_udpKey)
	{
	}
	
	/** IP where send this packet to */
	string ip;
	
	/** To which port this packet should be sent */
	uint16_t port;
	
	/** Data to sent */
	std::string data;
	
	/** CID of target node */
	CID targetCID;
	
	/** Key to encrypt packet */
	CID udpKey;
	
};

class UDPSocket :
	private Thread
{
	public:
		UDPSocket(void);
		~UDPSocket(void);
		
		/** Disconnects UDP socket */
		void disconnect() noexcept;
		
		/** Starts listening to UDP socket */
		void listen() throw(SocketException);
		
		/** Returns port used to listening to UDP socket */
		uint16_t getPort() const
		{
			return port;
		}
		
		/** Sends command to ip and port */
		void send(AdcCommand& cmd, const string& ip, uint16_t port, const CID& targetCID, const CID& udpKey);
		
	private:
	
		std::unique_ptr<Socket> socket;
		
		/** Indicates to stop socket thread */
		bool stop;
		
		/** Port for communicating in this network */
		uint16_t port;
		
		/** Queue for sending packets through UDP socket */
		std::deque<Packet*> sendQueue;
		
		/** Antiflooding protection */
		uint64_t delay;
		
		/** Locks access to sending queue */
		CriticalSection cs;
		
#ifdef _DEBUG
		// debug constants to optimize bandwidth
		size_t sentBytes;
		size_t receivedBytes;
		
		size_t sentPackets;
		size_t receivedPackets;
#endif
		
		/** Thread for receiving UDP packets */
		int run();
		
		void checkIncoming() throw(SocketException);
		void checkOutgoing(uint64_t& timer) throw(SocketException);
		
		void compressPacket(const string& data, uint8_t* destBuf, unsigned long& destSize);
		void encryptPacket(const CID& targetCID, const CID& udpKey, uint8_t* destBuf, unsigned long& destSize);
		
		bool decompressPacket(uint8_t* destBuf, unsigned long& destLen, const uint8_t* buf, size_t len);
		bool decryptPacket(uint8_t* buf, int& len, const string& remoteIp, bool& isUdpKeyValid);
};

}

#endif // _UDPSOCKET_H